Variable Stars – How and why they vary ~ Gary Poyner (British Astronomical Association)

The observation of Variable Stars is a fascinating and scientifically useful occupation which has been undertaken by amateur astronomers for over two centuries - but what actually makes a star vary in brightness? Over the past 150 years, theories and observations have led astronomers to go some way to understanding the science behind these changes, and this talk will show, at an introductory level, what remarkable objects Variable Stars actually are! The talk will concentrate on just three types – Pulsating, Symbiotic and Cataclysmic – which are the main groups in the ‘VS Zoo’.